The mobile communication network is developing for a higher transmission rate, a higher resource utilization rate and a larger network capacity, which leads to a higher requirement for radio spectrum resources in the future. However, available frequency resources for wireless communication are very limited. Thus, how to realize a transmission having a high rate and a large capacity with limited bandwidth resources is a research focus.
The device-to-device (D2D) technology refers to an inter-device direct communication in the data plane, which does not pass through a relay device (such as a base station or an access point). The D2D technology may be applied to a wireless network to improve resource utilization rate and network capacity, and further has the following advantages such as reducing the load of a cell base station, decreasing battery consumption, improving QoS of the wireless network, strengthening the structure of a lower level, providing a new service, and the like.
In the conventional technology, the following two structures are often adopted in the D2D communication. In one structure, signaling communication and data communication are preformed directly between devices, for example, the independent basic service set (IBSS) network in the wireless-fidelity (WiFi) network. In the other structure, each device maintains signaling communication with a base station while mutual communications between the devices are performed in the data plane, for example, the 3rd generation partnership project (3GPP). In process of establishing the D2D communication, a device needs to obtain available channel resources firstly. In the conventional technology, the D2D communication mainly is direct communication between different devices served by the same base station or the same access point, and the base station allocates channel resources for the D2D communication to both devices that perform the D2D communication.
The current D2D communication may realize the direct communication between different devices served by the same base station or the same access point, but for devices served by different base stations or different access points, D2D communication can not be established because resource negotiation for the D2D communication can not be performed.